The spontaneous oxidation process of pristine silicon （Si） limits its application as photocatalyst or electrode in aqueous solution or moist air. Covering a protection layer on Si surface is an effective approach to...The spontaneous oxidation process of pristine silicon （Si） limits its application as photocatalyst or electrode in aqueous solution or moist air. Covering a protection layer on Si surface is an effective approach to overcome this disadvantage. In this paper, α-Fe2O3 is demonstrated to be an excellent alternative as a protection material, α-Fe2O3 layer was deposited around each p-type Si micropillar （SiMP） in well-ordered array by chemical bath ＂deposition ＂method. The diameter of SiMP was 3 μm and the thickness of α-Fe2O3 layer was about 20 nm. The photoeletrochemical stability of SiMP/α-Fe2O3 was proved by 10 circles cyclic voltammetr7 testing. Compared with SiMP, its optical absorption and photocurrent density improved 2 times and 4 times, respectively, and its onset potential for hydrogen evolution moved positively about 0.4 V. These improved performances could be ascribed to the enhanced photogenemted-charge-separation efficiency deriving from built-in electric field at the interface between Si and α-Fe2O3. The above results show an effective strategy to utilize Si material as photocatalyst or electrode in aqueous solution or moist air.展开更多
基金Acknowledgements This work was supported by the National Nature Science Foundation of China （Grant No. 21590813）, the Programme of Introducing Talents of Discipline to Universities （B13012） and the China Scholarship Council.
文摘The spontaneous oxidation process of pristine silicon （Si） limits its application as photocatalyst or electrode in aqueous solution or moist air. Covering a protection layer on Si surface is an effective approach to overcome this disadvantage. In this paper, α-Fe2O3 is demonstrated to be an excellent alternative as a protection material, α-Fe2O3 layer was deposited around each p-type Si micropillar （SiMP） in well-ordered array by chemical bath ＂deposition ＂method. The diameter of SiMP was 3 μm and the thickness of α-Fe2O3 layer was about 20 nm. The photoeletrochemical stability of SiMP/α-Fe2O3 was proved by 10 circles cyclic voltammetr7 testing. Compared with SiMP, its optical absorption and photocurrent density improved 2 times and 4 times, respectively, and its onset potential for hydrogen evolution moved positively about 0.4 V. These improved performances could be ascribed to the enhanced photogenemted-charge-separation efficiency deriving from built-in electric field at the interface between Si and α-Fe2O3. The above results show an effective strategy to utilize Si material as photocatalyst or electrode in aqueous solution or moist air.
